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arm asm memory access functions for m/s68k

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This commit is contained in:
kub 2019-03-20 19:08:46 +01:00
parent e0396782f3
commit 78d817c370
4 changed files with 205 additions and 9 deletions
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96
pico/memory_arm.S
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@ -59,6 +59,7 @@ m_read8_eeprom:
ldmfd sp!,{r1,lr}
tst r1, #1
moveq r0, r0, lsr #8
and r0, r0, #0xff
bx lr
@ -220,6 +221,101 @@ m_write16_not_z80ctl:
strb r2, [r3, #OFS_Pico_m_sram_reg]
bx lr
.global m68k_read8
.global m68k_read16
.global m68k_write8
.global m68k_write16
m68k_read8:
ldr r3, =m68k_read8_map
bic r0, r0, #0xff000000
mov r2, r0, lsr #16
ldr r3, [r3, r2, lsl #2]
eor r2, r0, #1
movs r3, r3, lsl #1
ldrccb r0, [r3, r2]
bxcc lr
bx r3
m68k_read16:
ldr r3, =m68k_read16_map
bic r0, r0, #0xff000000
mov r2, r0, lsr #16
ldr r3, [r3, r2, lsl #2]
bic r0, r0, #1
movs r3, r3, lsl #1
ldrcch r0, [r3, r0]
bxcc lr
bx r3
m68k_read32:
ldr r3, =m68k_read16_map
bic r0, r0, #0xff000000
mov r2, r0, lsr #16
ldr r3, [r3, r2, lsl #2]
bic r0, r0, #1
movs r3, r3, lsl #1
ldrcch r1, [r3, r0]!
ldrcch r0, [r3, #2]
orrcc r0, r0, r1, lsl #16
bxcc lr
stmfd sp!, {r0, r3, r4, lr}
mov lr, pc
bx r3
ldmfd sp!, {r1, r3}
str r0, [sp]
add r0, r1, #2
mov lr, pc
bx r3
ldmfd sp!, {r1, lr}
mov r0, r0, lsl #16
mov r1, r1, lsl #16
orr r0, r1, r0, lsr #16
bx lr
m68k_write8:
ldr r3, =m68k_write8_map
bic r0, r0, #0xff000000
mov r2, r0, lsr #16
ldr r3, [r3, r2, lsl #2]
eor r2, r0, #1
movs r3, r3, lsl #1
strccb r1, [r3, r2]
bxcc lr
bx r3
m68k_write16:
ldr r3, =m68k_write16_map
bic r0, r0, #0xff000000
mov r2, r0, lsr #16
ldr r3, [r3, r2, lsl #2]
bic r0, r0, #1
movs r3, r3, lsl #1
strcch r1, [r3, r0]
bxcc lr
bx r3
m68k_write32:
ldr r3, =m68k_write16_map
bic r0, r0, #0xff000000
mov r2, r0, lsr #16
ldr r3, [r3, r2, lsl #2]
bic r0, r0, #1
movs r3, r3, lsl #1
movcc r2, r1, lsr #16
strcch r2, [r3, r0]!
strcch r1, [r3, #2]
bxcc lr
stmfd sp!, {r0, r1, r3, lr}
mov r1, r1, lsr #16
mov lr, pc
bx r3
ldmfd sp!, {r0, r1, r3, lr}
add r0, r0, #2
bx r3
.pool
@ vim:filetype=armasm